Random crash with SIGABRT

Hi!
We get next random crashes from our users

Crashed Thread:        30  Thread Pool Worker

Exception Type:        EXC_BAD_ACCESS (SIGABRT)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0000000000000020
Exception Note:        EXC_CORPSE_NOTIFY

VM Regions Near 0x20:
--> 
    __TEXT                 0000000106039000-0000000106515000 [ 4976K] r-x/r-x SM=COW  /Applications/Workplace.app/Contents/MacOS/Workplace

Application Specific Information:
abort() called
...
Thread 30 Crashed:: Thread Pool Worker
0   libsystem_kernel.dylib          0x00007fff72b6d33a __pthread_kill + 10
1   libsystem_pthread.dylib         0x00007fff72c29e60 pthread_kill + 430
2   libsystem_c.dylib               0x00007fff72af4808 abort + 120
3   com.os33                        0x00000001063d7d0c altstack_handle_and_restore.cold.1 + 44
4   com.os33                        0x00000001060c6b9e altstack_handle_and_restore + 206
5   libobjc.A.dylib                 0x00007fff71873678 objc_release + 24
6   libobjc.A.dylib                 0x00007fff71873dba objc_autoreleasePoolPop + 175
7   com.apple.CoreFoundation        0x00007fff38b81b15 _CFAutoreleasePoolPop + 22
8   com.apple.Foundation            0x00007fff3b22d73e -[NSAutoreleasePool drain] + 126
9   com.os33                        0x0000000106065ced xamarin_thread_finish(void*) + 141
10  com.os33                        0x0000000106065a9c thread_end(_MonoProfiler*, unsigned long) + 28
11  com.os33                        0x00000001062aa6d5 mono_profiler_raise_thread_stopped + 53
12  com.os33                        0x00000001062e60bb mono_thread_detach_internal + 1355
13  com.os33                        0x00000001062ee43b start_wrapper_internal + 411
14  com.os33                        0x00000001062ee27e start_wrapper + 62
15  libsystem_pthread.dylib         0x00007fff72c2a109 _pthread_start + 148
16  libsystem_pthread.dylib         0x00007fff72c25b8b thread_start + 15

It's started to reproduce when we started build our Xamarin.Mac application in macOS Catalina with next environment:

=== Visual Studio Community 2019 for Mac ===

Version 8.6.4 (build 14)
Installation UUID: 1a985d9f-94a4-4de8-967f-3174cb0eb3dd
    GTK+ 2.24.23 (Raleigh theme)
    Xamarin.Mac 6.18.0.23 (d16-6 / 088c73638)

    Package version: 610000104

=== Mono Framework MDK ===

Runtime:
    Mono 6.10.0.104 (2019-12/5d03a6fe116) (64-bit)
    Package version: 610000104

=== Roslyn (Language Service) ===

3.6.0-3.20210.9+4eafdcb1bcbd8d3573f2ba6065e56d9b9ce4f8a3

=== NuGet ===

Version: 5.6.0.6591

=== Apple Developer Tools ===

Xcode 11.5 (16139)
Build 11E608c

=== Xamarin.Mac ===

Version: 6.18.2.1 (Visual Studio Community)
Hash: 29c4ea731
Branch: d16-6
Build date: 2020-05-26 17:03:04-0400

=== Operating System ===

Mac OS X 10.15.5
Darwin 19.5.0 Darwin Kernel Version 19.5.0
    Tue May 26 20:41:44 PDT 2020
    root:xnu-6153.121.2~2/RELEASE_X86_64 x86_64

Before that we builded on Mojave and everything was fine:

  === Visual Studio Community 2017 for Mac ===

Version 7.8.4 (build 1)
Installation UUID: ae120131-5d3b-4a43-a420-afba336c5e7c
    GTK+ 2.24.23 (Raleigh theme)
    Xamarin.Mac 5.0.0.0 ( / b40230c0)

    Package version: 518010003

=== Mono Framework MDK ===

Runtime:
    Mono 5.18.1.3 (2018-08/fdb26b0a445) (64-bit)
    Package version: 518010003

=== NuGet ===

Version: 4.8.2.5835

=== Apple Developer Tools ===

Xcode 10.1 (14460.46)
Build 10B61

=== Xamarin.Mac ===

Version: 5.8.0.0 (Visual Studio Community)
Hash: 0aa84521
Branch: d16-0
Build date: 2019-04-02 16:01:19-0400

=== Operating System ===

Mac OS X 10.14.6
Darwin 18.7.0 Darwin Kernel Version 18.7.0
    Tue Aug 20 16:57:14 PDT 2019
    root:xnu-4903.271.2~2/RELEASE_X86_64 x86_64

I've tried some workarounds like

new System.Threading.Thread (() => 
{
  while (true) {
    System.Threading.Thread.Sleep (100);
    GC.Collect ();
  }
}).Start ();

to speed up crash reproducing but i couldn't yet.

AOT is enabled.
Can anyone help me? Maybe someone could point me a direction to look on?

Thanks in advance!